Sewing-machine.



A. KRASA.

SEWING MACHINE.

APPLICATION FILED MAY 12, 1913.

Patented Sept. 5,1916.

2 SB EETSSHEET I.

A. KRASA.

"SEWING MACHINE. APPLICAHON FILED MAY 12. 1913.

2 SHEETSSHEET 2- wuc/wto'o Patented Sept. 5

ml; muems PETrris r0 I "am I ma ALBERT KRASA, OF MICHIGAN CITY, INDIANA,ASSIGNOR TO UNION SPECIAL MACHINE COMPANY, OF CHICAGO, ILLINOIS, ACORPORATION OF ILLINOIS.

SEWING-MACHINE.

amas.

Specification of Letters Patent.

Patented Sept. 5, 1916..

To all whom it may concern:

Be it known that I, ALBERT KRAsA, a citizen of the United States,residing at Michigan City, in the county of Laporte, State of Indiana,have invented certain new and useful Improvements in Sewing-Machines, ofwhich the following is a description, reference being had to theaccompanying drawing and to the figures of reference marked thereon.

The invention relates to new and useful improvements in sewing machines,and more particularly to the looper mechanism fora cylindrical bed platemachine, such as shown for example, in the patent granted L. Muther, R.G. Woodward, and E. C. Holland, May 25th, 1897, No. 583,415.

An object of the invention is to provide a looper-supporting shaft andoperating devices therefor, which are so constructed and arranged thatsaid looper shaft may have an extended bearing in the standard of themachine.

In the drawings which show by way of illustration, one embodiment of theinvention, Figure 1 is a vertical sectional view longitudinally of thebed plate, showing the lower part of a sewing machine having myimprovements applied thereto, the feeding mechanism being omitted forthe sake of clearness; Fig. 2 is a view showing the means foroscillating the looper shaft; Fig. 3 is a detail showing the loopershaft and the bearing therefor, in plan view.

The sewing machine to which my invention is applied, consists of asupporting base 1, from which rises a standard 2. Mounted in thestandard 2 in suitable bearings therein is a main shaft 3. Projectinglaterally from said standard 2 is a cylindrical bed plate 1. Thiscylindrical bed plate, as shown in the patent above referred to, extendsto a point slightly beyond the needle 5.

The looper-supporting shaft 6 is mounted to rotate in a bearing 7carried by the cylindrical bed plate adjacent its outer end, and also ina bearing 8 carried by the cylindrical bed plate at its inner end, orwhere said cylindrical bed plate is attached to the standard 2. Thelooper-supporting shaft 6 at its inner end is provided with an operatingyoke 9. This yoke is preferably made so as to fit snugly on the end ofthe shaft, and is welded thereto. Instead, however, of welding the yoketo the looper shaft, said yoke and looper shaft may be made from aslngle plece of metal.

The essential feature of construction con sists in forming the yokeintegral with the end of the shaft, and this may be accomplished ineither way above noted. This yoke has a laterally projecting arm carrymga stud 10, which cooperates with an eccentric strap 11. The eccentricstrap 11 in turn cooperates with an eccentric 12 on the. main shaft 3.As the main shaft 3 rotates, this eccentric strap 11, through the yoke9, will oscillate the looper shaft in its bearings. The yoke 9 is alsoprovided with an ear 13, which is preferably arranged substantially inaxial alinement with the longi tudinal axis of the looper-supportingshaft. A cross shaft 14 is mounted in suitable bearings in the standard2, and is parallel with the main shaft 3. On this cross shaft 14 is alever 15. The lower end of the lever 15 is slotted as at 16. A link 17is forked at,

its inner end, and is pivoted to the ear 13. The outer end of the link17 is pivotally connected to a rod 18, adjustably supported in the slot16.

The lever 15 at its upper end is connected to an eccentric strap 19,which cooperates with an eccentric 20 on the main shaft 3. As the mainshaft 3 rotates, the lever 15 will be oscillated, and through the link17, will move said looper-supporting shaft endwise in its bearings. Theamount of movement imparted to the looper shaft may be varied byadjusting the position of the rod 18 in the slot 16.

On the outer end of the looper shaft 6 and adjacent the needle 5, is alooper carrier 21, which supports a looper 22. This looper carrier 21 isadjustably held on the end of the shaft 6 by a set screw 23. The looperis so mounted on the carrier 21 that the 0s cillating movements of thelooper shaft will move the looper into and out of the needle loop, whilethe endwise movements of the looper shaft will give to said looper itsneedle-avoiding movements. When the looper shaft is in place, the loopercarrier, by loosening the set screw 23, may be adjusted longitudinallyof said shaft to bring said looper into proper cooperative relationwiththe needle 5, after which the set screw 23 may be used for lockingthe carrier to the shaft, so that it isrigidly connected thereto.

In the patent above referred to, it will be noted that the yoke foroscillating the looper shaft and for moving the same endwise, is clampedto the end of the looper shaft, and this requires a collar ofConsiderable width, and necessarily restricts the amount of bearingsurface of the looper shaft in the cylindrical bed plate at the innerend of the shaft. By my present invention, the yoke is welded orotherwise formed integral with the end of the shaft, and as aconsequence said connection between the yoke and the shaft may be madevery much smaller. This gives space for an additional bearing for thelooper shaft. This additional or auxiliary bearing 24 is clamped to theplate 25 cast integral with the cylindrical bed plate, by clamping-bolts26, which, as herein shown, are three in number. The bearing 24 projectsinto the interior of the standard 2, and

to a point adjacent the end of the looper shaft. The bearing 8 which isformed as a part-of the plate 25, projects outwardly, and this forms anextended bearing for the shaft 6.

The bearing 24 is formed with a rib 27, which engages a socket 28 in theplate 25 to aid in holding the bearing in fixed relation with the plate25.

By the above construction, wherein the yoke is formed integral with theinner end of thelooper shaft, the looper is made adjustable on thelooper shaft, so it may be properly set relative to the needle, and I am7 7 thereby able to produce a looper shaft having a yoke formed integraltherewith, so as to afford an extended bearing surface for the loopershaft at the inner end thereof, and at the same time secure the properadjustments between the looper carrier and the looper, to properlyposition the looper relative to the needle. While I have described theyoke 9 as formed integral with the shaft, particular attention is calledto the fact that the shaft is connected directly to one arm of the yoke,and by'this direct connection of the shaft 6 to the yoke, I am able toprovide further space for the inwardly extending auxiliary bearing 24. 7

It will be obvious that from certain aspects of the invention this yokemay be otherwise secured to the shaft 6, than by welding or formedintegral therewith, as above described.

4 Having thus described my invention, what I claim as new and desire tosecure by Letters Patent, is r V I 1. A sewing machine including incombination, a looper shaft, means for supporting said looper shaftbetween its ends, whereby said looper shaft may be oscillated and movedendwise, a yoke having one of its arms formed integral with the innerend of the shaft, means connected to the'arm attached to the shaft foroscillating the same, and

means connected to the other arm of the yoke for moving the shaftendwise, and a looper carrier mounted on the other end of said shaft.

2. A sewing machine including in combination, a looper shaft, means forsupporting said looper shaft between its ends, whereby said looper shaftmay be oscillated and moved endwise, a yoke having one of its armsformed integral with the inner end of the shaft, means connected to thearm attached to the shaft for oscillating the same and means connectedto the other arm of the yoke for moving the shaft endwise, and a loopercarrier mounted on the other end of said shaft, said looper carrierbeing adjustable lengthwise of the shaft.

3. A sewing machine including in combination, a standard, a cylindricalbed plate projecting laterally therefrom, a supporting plate forattaching said bed plate to the standard, a bearing carried by saidsupporting plate and projecting into said standard, a looper shaftmounted in said bearing, a yoke formed integral with the inner end ofsaid shaft adjacent said bearing, means connected to said yoke foroscillating said shaft and for moving said shaft longitudinally, and alooper carrier adjustably connected with the outer end of said shaft.

4. A sewing machine including in combination, a standard, a cylindricalbed plate projecting laterally from said standard, a supporting platefor attaching said cylindrical bed plate to said standard, a bearingprojecting outwardly from said plate, a bearing attached to the innerface of said plate and projecting into said standard, a looper shaftmounted in said bearings, a yoke formed integral with the inner end ofsaid shaft, means engaging said yoke for oscillating said shaft and formoving said shaft endwise in said bearing, a bearing near the outer endof said bed plate for said shaft, and a looper carrier adjustablymounted on the outer end of said looper shaft.

5. A sewing machine including in combination a looper shaft, means forsupporting the same, a yoke, one arm of which is directly attached tothe end'of the shaft, and a ball mounted eccentrically upon said arm,whereby said yoke may be oscillated, the other arm of said yoke having aconnection whereby said shaft may be moved endwise.

6. A sewing machine including in combination a looper shaft, means forsupporting the same, a yoke, one arm of which is directly attached tothe end of the shaft, a ball mounted eccentrically upon said arm,whereby said yoke may be oscillated, and a swivel connection at theopposite end of the yoke, whereby said yoke may be moved longitudinally.

7. A sewing machine including in combination a looper shaft. means forsupporting the same, a yoke, one arm of which is directly attached tothe end of the shaft, a ball mounted eccentrically upon said arm,whereby said yoke may be oscillated, a swivel connection at the oppositeend of the yoke, whereby said yoke may be moved longitudinally, meansconnected to said ball for oscillating the looper shaft, and meansconnected to said swivel connection for moving said looper shaftlongitudinally.

8. A sewing machine including in combination, a looper shaft, means forsupporting said shaft, a yoke formed upon one end of said shaft, meansto operate said yoke in two different directions, a looper supportmounted upon the opposite end of said shaft and means whereby saidlooper support is adjusted in two directions.

In testimony whereof I affix my signature in the presence of twoWitnesses.

ALBERT KRASA.

Witnesses:

C. MoNEIL, JAMES W. KENNINGTON.

Gopies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, I). C.

